1. Field of the Invention
The present invention relates to an electronic apparatus having a detachable cover on an outside of a structural body of the electronic apparatus, such as a case or a frame, and to a cover and structural body thereof. In particular, the present invention relates to an electronic apparatus having a construction in which a cover attached thereto can be brought into a tight contact with the structural body, thereby being capable of maintaining a satisfactory outward appearance, and to the cover and structural body thereof.
2. Description of the Related Art
In some electronic apparatus such as a mobile phone, an elaborately designed cover is further attached to an outside of a structural body (case) for a variation in artistic design, thus providing a sense of fun like changing of clothes.
For example, Registered Utility Model Application No. 3063050 discloses a “Mobile Communication Apparatus with an Easily Replaceable Decorative Apparatus,” in which the main body of a mobile communication apparatus itself is sandwiched between a front cover and a rear cover that are provided with various designs, configurations, colors, etc., thus providing a mobile communication apparatus that can be varied in outward appearance. In this mobile communication apparatus, locking members respectively provided on the front cover and the back cover sandwiching the main body are connected with each other to firmly secure the whole together. Further, JP 2003-32342 A discloses a mobile information apparatus that easily allows a change in outward appearance by means of an external decorative cover. In this mobile information apparatus, a protrusion provided on a battery cover to be attached from behind to a main portion of the apparatus main body through sliding is engaged with a groove of an engagement mechanism provided on an external decorative cover covering the main portion of the apparatus main body, thereby securing the whole together.
Apart from these, there exists a construction in which a base case and a fixing portion for attaching a cover to the base case are predetermined, and solely the cover, which is selected from separately prepared covers of different designs and colors, is replaced to easily realize a variation in design and color.
FIG. 7A is a perspective view of an example of the outward construction of a mobile phone. FIG. 7B is a side view of an upper case 100, which is shown in FIG. 7A. As shown in FIG. 7B, in the upper case 100, a main body case is formed by a first case 101 and a second case 103, and requisite electronic components, etc. for the upper case are contained in this main body case. Further, a detachable cover 102 can be attached to the first case 101.
FIG. 8 is a perspective view of a conventional example 1 of the construction of the first case 101 and cover 102.
In the cover of this construction, a part of the peripheral edge portion thereof is generally inwardly bent (or curved), and when attached, it is necessary for the cover to be integrated with the case constituting the base so as to maintain a well-harmonized outward appearance. However, this cover, which is formed as a thin-walled molding, is subject to generation of curvature or gap in the peripheral edge portion. Thus, when, as shown in FIG. 8, the cover 102 is attached to the outside of the first case 101, a level difference (gap) is generated, as shown in the sectional view of FIG. 9, between the peripheral edge portion of the cover 102 and the first case 101 due to curvature at the time of molding of the cover 102. Thus, when the first case 101 and the second case 103 are combined to form the main body case, there is generated a step due to the curvature of the cover 102 in the peripheral edge portion of the second case 103, resulting in a problem in terms of outward appearance.
As means for solving this problem, there is a construction in which, as shown in FIG. 10 as the conventional example 2, there are provided in the inner corner portion of the cover 102 a plurality of vertical ribs 102a perpendicular to the crease direction, preventing (rectifying) curvature of the cover 102 itself by means of the vertical ribs 102a and achieving an increase in bending strength. Further, in the first case 101, there is formed a large clearance 101a in correspondence with these vertical ribs 102a. However, in the construction shown in FIG. 10, it is impossible to completely suppress the molding curvature of the cover 102. Further, it is necessary to form the large clearance 101a in the first case 101, resulting in a problem in terms of the strength and formability of the first case 101.
As another means, there exists a construction in which, as shown in FIG. 11 as the conventional example 3, there is arranged in the inner corner portion of the cover 102 a lateral rib 102b formed so as to extend continuously along the crease direction, whereas a groove 101b is formed at the position of the first case 101 corresponding to the lateral rib 102b; by fitting the lateral rib 102b of the cover 102 into the groove 101b of the first case 101, the opening of the peripheral edge portion of the cover 102 is suppressed. In this construction, however, due to the formation of the groove 101b in the first case 101, the thickness of the case peripheral portion toward the interior increases, which leads to a problem from the viewpoint of securing the space for the built-in mounting components.